Lever lock unit

ABSTRACT

A lever lock unit includes a housing, a dogging element adapted to actuate a lock bolt, a plurality of lever tumblers that are actuable via the dogging element and movable relative thereto, and a blocking element for blocking movement of the dogging element in the absence of a key or when the wrong key is inserted in the unit. The unit is characterized by a cradle accommodated in the dogging element and adapted to receive the lever tumblers. The dogging element is rotatable and is adapted so that when rotated, the cradle accommodated in the dogging element, and there with also the lever tumblers accomodated in the cradle, will be caused to move linearly in relation to the dogging element and in relation to a key inserted into the unit, for movement of the lever tumblers to a blocking element release position when the correct key is inserted.

FIELD OF INVENTION

The present invention relates to a lever lock unit, and moreparticularly to a lever lock unit in which movement of the levertumblers is such as to make forcing and manipulation: of the lockdifficult to achieve.

The invention also relates to a key for use with such a lock.

BACKGROUND ART

Known lever locks are constructed so that when turning the lock key, thekey seeks for the lever tumblers in order to move the levers to alock-release position in accordance with a code on the key. This generalprinciple, whereby the key seeks and actuates the lever tumblers as thekey is turned is beset with many draw-backs.

One of these drawbacks is that turning of the key results in wearbetween key and lever tumblers, which results in wear marks on both keyand lever tumblers in the passage of time. These marks can facilitatemanipulation and forcing of the lock.

Another drawback is that a multi-key/tumbler system cannot be readilyimplemented in some lock units of this kind, due to the particulardesign of the lever tumblers.

German Patent Specification 394 690 (Deutsche Türschlieβ-er-IndustrieWilhelm Müller) teaches a lever lock that includes a plate which, whenmoved, dogs a number of lever tumblers into a lock release position whenthe correct key is inserted. This relative movement between plate andlever tumblers, and also between plate and key, is a combination oflinear movement and rotary movement. This does not avoid the drawbackwhereby wear marks are formed on the key and lever tumblers.

OBJECTS OF THE INVENTION

One object of the present invention is to provide a lever lock unitwhich is more secure than earlier known lock units or assemblies of thiskind.

Another object is to provide a lever lock unit with Which a key/levertumbler system,n can be easily included.

Another object of the invention is to provide a lock unit which can beconstructed from a wide choice of materials.

Still another object of the invention is to provide a key that can beused with such a lock unit.

DISCLOSURE OF THE INVENTION

This object is achieved with a lever lock unit that is accommodated in ahousing and includes a dogging element adapted to actuate a lock bolt, aplurality of lever tumblers that are actuable via the dogging elementand movable relative thereto, and a blocking element for blockingmovement of the dogging element when no key is inserted, or when thewrong key is inserted, wherein the lever lock unit is characterized by acradle carried in the dogging element and adapted to accommodate thelever tumblers, wherein the dogging element is rotatable and so adaptedthat rotation of the dogging element will cause the cradle accommodatedin the dogging element, and therewith the lever tumblers accommodated inthe cradle, to move linearly in relation to the dogging element and inrelation to a key inserted in the lock, so as to bring the levertumblers to a blocking element release position when the correct key hasbeen inserted.

The decisive difference between conventional locks in which the keyseeks the lever tumblers and lifts the same and the inventive lockconstruction, is that in the case of the inventive lock construction thelever tumblers, instead, seek the key and stop in the position given bythe code.

Another difference is that turning of the key causes the cradle to movelinearly through the coaction of means provided thereon withcorresponding means in one part or the other part of the fixed housing.

One of the advantages afforded by the invention is that wear between keyand lever tumblers is minimized, thereby avoiding the easily read wearmarks that a conventional key will leave on a lever tumbler whenstriking the same. This greatly increases security of the lock againstunauthorized manipulation.

Minimization of key wear on the lever tumblers also enables key andtumblers to be made from a wider variety of materials.

The invention also relates to a lock according to claim 11 or claim 12.The key is adapted for use with a lock of the general principle definedin claim 1.

Further preferred embodiments of the invention are set forth in thefollowing dependent claims.

BRIEF DESCRIPTION OF TEE DRAWINGS

The invention will now be described in more detail with reference to anexemplifying embodiment thereof and also with reference to theaccompanying drawings, in which

FIG. 1 is a perspective view of an inventive lock unit;

FIG. 2 is a perspective exploded view of the lock unit shown in FIG. 1,and also shows a key for use with the lock;

FIGS. 3a-3 f illustrate different stages of a lock locking operation;

FIG. 4 illustrates coaction of the lock unit with a lock bolt mounted ina lock chest;

FIG. 5 is a perspective exploded view of an alternative embodiment ofthe lock unit shown in FIG. 1, and shows a key for use with thisalternative unit;

FIG. 6 is a more detailed view of a groove in the spine of the key shownin FIG. 5; and

FIG. 7 illustrates coaction of a lever tumbler with a latch pin in theunit shown in FIG. 5.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Preferred embodiments of the inventive lever lock unit, or latch unit,will now be described in more detail.

FIG. 1 shows a lock unit comprising a lock chest having an upper part 10and a lower part 11, said parts being screwed together. Both of thechest halves include a key receiving hole 12. The two chest halves alsodefine an opening 13 through which a lock bolt is able to move.

The components of the lock unit 2 are shown in FIG. 2. Rotatably mountedin the lock chest is a dogging element which in the illustratedembodiment has the form of a drum 20 which is intended to accommodate acradle 30 between drum walls 22, 24 and 26. The drum walls are designedto permit linear relative movement between drum and cradle. As the drumrotates, the cradle 30 is caused to move linearly in relation to thedrum by pins 14, 16 that are mounted in the upper chest part 10 and thatcoact with a curve 36, 38 in the form of a cavity or opening 34 in thecradle.

The cradle accommodates a plurality of lever tumblers 40, for instancenine tumblers. These lever tumblers are mutually identical with theexception of the position of code reading grooves or recesses 42 in theside edges of respective tumblers. These recesses or grooves arepositioned at mutually different heights corresponding to the pitch ofthe key code. The tumblers have a width which allows the tumblers topass between walls 32 of the cradle 30. Each lever tumbler is providedwith two resilient tongues 44, for abutment with the walls 32. Thisprovides frictional resistance against relative movement between cradleand lever tumbler.

Thus, the cradle and lever tumblers rotate as the drum rotates, whilethe cradle opening, at the same time, moves relative to the pins 14, 16in the upper chest part. Since the lever tumblers are guided in thecradle in the aforesaid manner, the tumblers will accompany the cradleas it moves until they reach their positions relative to the key,whereupon the resilient tongues 44 hold the tumblers in their adoptedpositions.

A code slide 50 is mounted in the drum 20 for movement at right anglesto movement of the cradle in relation to the drum, and forms a codereading part of the lock. The code slide 50 carries a sensing ordetecting projection 52 which functions to detect whether or not thecorrect key has been used in the following manner. As earlier mentioned,the various lever tumblers 40 are displaced to mutually differentextents in relation to the drum, and therewith in relation to the codeslide 50, in accordance with the code on the inserted key. When the keycode is the correct code, the lever tumblers are moved so that therecesses or grooves 42 in the tumbler side edges form athrough-penetrating passageway. The code slide can then be pressed intothe passageway formed by said side recesses or grooves 42 by a cam 18mounted on the upper chest part 10. This cam 18 also blocks rotationwhen the wrong key is inserted. The code slide thus corresponds to thelatch pin of a typical lever lock.

FIG. 2 also shows a key 70 for use with the inventive lock unit. The keyincludes a key bit 72 which has code surfaces or code grooves 74 cut inone side surface thereof. In the basic embodiment, the other sidesurface (not shown) of the key lacks code grooves but is machined to adepth that corresponds to the depth of the code grooves.

The key bit has a shape and dimensions that coincide with a key-bitreceiving recess 46 in respective lever tumblers 40. The depth of thisrecess is such as not to impede linear movement of the tumblers inrelation to the key as the drum is turned. Instead, this linear movementof the lever tumblers is stopped when the key bit has been inserted intothe recess 46 to an extent at which the lever tumblers lie against thecode groove 74. Thus, it is the lever tumblers that move towards the keyand that are brought to respective positions in accordance with the keyon the key bit.

Function

A lock locking operation will now be described with reference to FIGS.3a-3 f.

FIG. 3a shows a starting position in which all lever tumblers are atmutually the same height. This position allows a key to be inserted intothe lock.

FIG. 3b shows the position after the drum 20 has been turnedanti-clockwise through about 90°. Rotation of the drum is caused byturning the inserted key, which causes the drum to rotate.

Further anti-clockwise rotation causes the cradle, and therewith thelever tumblers, to be moved linearly by the pin 14 in relation to thedrum.

FIG. 3c shows the state of the lock after anti-clockwise rotationthrough about 130°. In this state of the lock, the cradle has been movedmaximally in relation to the drum, which will be evident by the factthat the pin 14 has reached the rounded part of the curved surface 36.The lever tumblers are in their final positions, or lock releasepositions, in this stage. The lever tumblers therewith press against thekey, when the cradle has moved linearly The lever tumblers are retainedin their adopted positions, by the frictional effect of the tongues 44against the cradle walls 32.

As before mentioned, the code reading recesses form a through-passingpassageway for the code slide when the correct key is inserted. The codeslide 50 can therewith be pressed-in, i.e. moved in a directionperpendicular to the direction in which the cradle and the levertumblers have been moved on the other hand, if an incorrect key has beeninserted, no through-passing passageway will be formed and the codeslide cannot be pressed-in, and rotary movement will be stopped byabutment of the code slide with the cam 18.

FIG. 3d shows the code reading projection or talon 52 on the code slide50 pressed into the passageway formed by the recesses 42. Turning of thekey, and therewith the drum, can therefore be continued.

FIG. 3e illustrates the lock components when an angle of 130° remains ofthe anti-clockwise rotary movement. The code slide 50 has been caused toleave the passageway formed by the lever tumblers by a second cam 19(FIG. 2) on the lower chest part, and the fixed pins 14, 16 in the upperchest half have moved out of engagement with the first curve 36 in thecradle.

FIG. 3f shows that continued rotation brings the second curved surface38 in the cradle opening 34 and the first pin 14 into contact with oneanother, whereby the cradle and, thereby, the lever tumblers arereturned to the starting position shown in FIG. 3a.

In the aforedescribed rotation of the drum, a bolt actuator 28 actuatesa lock construction so as to lock the lock, see the followingdescription of FIG. 4.

The aforedescribed sequence of events is reversed when rotating the drumin the opposite direction, i.e. clockwise in FIGS. 3a-3 f. Onedifference is that the second pin 16 is the first pin to engage thecurved surfaces 36, 38 in the cradle opening, and not the first pin 14.

FIG. 4 shows the coaction of a lock unit 2 housed in a lock chest 80with a locking bolt or latch bolt 82, via a link arm 84. When the drum20 is caused to rotate clockwise, by turning the key 70 clockwise in thelock, the bolt actuator 28 will engage in a recess 86 on the link arm 84after the drum has been turned through about 170°. Further clockwiserotation of the key urges the link arm to the left in the Figure,wherewith the bolt 82 mounted on pivot 88 is caused to rotate clockwiseinto the lock chest, therewith unlocking the door. When locking thedoor, the movements are the reverse to those described, i.e. the key isturned anti-clockwise and the lock bolt is rotated clockwise out fromthe lock chest.

Description of an Embodiment that Includes a Latch Pin

The lock of the aforedescribed embodiment has a given level of security,i.e. the code grooves on the key bit determine whether or not the drumcan be rotated. With the intention of providing greater security, thereis proposed a further preferred embodiment in which the lock unit alsoincludes latch pins that are intended to block movement of the levertumblers 40 when a wrong key is inserted into the lock.

FIG. 5, which corresponds to FIG. 2 illustrating the first embodiment,shows the further embodiment that includes latch pins, wherein thosecomponents of the FIG. 2 embodiment that find correspondence in the FIG.5 embodiment have been identified by the same reference numerals towhich a prime has been added.

It will be evident from FIG. 5 that a plurality of latch pins 60 arelinearly mounted in the drum 20′ for linear movement transversely to thedirection of movement of the lever tumblers 40′. The lever tumblersinclude a recess or notch 48 in the side surfaces of an opening in thelever tumblers, see FIG. 7. These notches 48 are disposed at a height orlevel which enables a latch pin 60 to engage in a respective notch whenthe lever tumblers 40′ are located in their respective start positions.

Movement of the latch pins 60 is guided forcibly by a groove 76 providedon the spine of the key 70′ and the shape of which will be seen moreclearly from FIG. 6. Insertion of the key into the lock unit guides acircumferentially extending flange 62 on the latch pin to a position ona level with the pin concerned, this position being determined by thegroove 76 in the key spine. If the key does not have the correct spinecode, i.e. the correct groove shape, at least one of the latch pins 60will be brought to a position in which a latching end 64 of said pinengages a corresponding notch 48 in a lever tumbler 40′, therebyblocking linearly movement of the lever tumbler in relation to the drum.

Description of Further Embodiments

As will be evident from the drawings, the general shape of the levertumblers is generally symmetrical in an axial direction, with theexception of the recess 42. In the preferred embodiment, the recesses 42are disposed at different heights in both left and right side edges, asevident from FIG. 2. This provides a lever tumbler which can be used fortwo different coding positions, simply by turning the tumblers aboutface. This is beneficial, because it reduces the number of differentlever tumblers required and therewith the number that must be kept instock. For instance, four different types of lever tumbler will sufficefor seven different coding positions.

Furthermore, several code-slide receiving recesses 42 can be provided onone and the same side surface. Such lever tumblers may be used in lockshaving mutually different key levels. This enables the provision of locksystems, i.e. a system in which several different key codes fit one andthe same lock.

The lever tumblers 40, 40′ of the described lock unit are preferablymade of brass, although they may alternatively be made of somereinforced plastic material.

The illustrated key 70, 70′ has grooves cut in only one side surface ofthe key bit 72. However, corresponding grooves may also be cut on theother side of the key bit, said codes on respective sides being eithersymmetrical or asymmetrical. This provides greater security, since morekey combinations are therewith made possible.

In all of the illustrated embodiments, the drum, the cradle, and thelever tumblers are rotated by turning a key inserted into the lock.However, other turning means are conceivable. For instance, the drum maybe connected to an electric motor or to a handle or knob, such as in thecase of a vault or safe, for instance. The key need not therewith beprovided with a typical key grip or the like. The key is also subjectedto less force, which enables it to be made of a weaker material, such asa plastic material.

It will be understood that the lock unit need not necessarily be placedin a lock chest, as illustrated in the FIG. 4 example. Instead, the lockunit may be mounted on the outside of a door, in which case the unitwill have a cylindrical configuration.

What is claimed is:
 1. A lever lock unit which is housed in a casing andwhich includes a dogging element which functions to actuate a lock bolt;a plurality of lever tumblers that are actuable by the dogging elementand movable relative thereto; and a blocking element for blockingmovement of the dogging element in the absence of a key or when theincorrect key has been inserted, wherein a cradle which is accommodatedin the dogging element and adapted to receive the lever tumblers,wherein the dogging element is rotatable and adapted so that rotation ofthe dogging element will cause both the cradle accommodated in thedogging element, and the lever tumblers accommodated in the cradle, tomove linearly in relation to the dogging element and to a key insertedin the lock unit, for movement of the lever tumblers to a blockingelement release position when a correct key is inserted.
 2. A unitaccording to claim 1, wherein the lever tumblers are retained in saidrelease position by frictional forces acting between the lever tumblersand the cradle.
 3. A unit according to claim 2, wherein the frictionalforces are generated by spring devices formed integral with the levertumblers.
 4. A unit according to claim 1, wherein the cradle and levertumblers accommodated therein are caused to move linearly by coactionbetween a first and a second curved surface in the cradle and means inthe casing.
 5. A unit according to claim 1, wherein the dogging elementis caused to rotate by turning a key inserted into the unit.
 6. A unitaccording to claim 1, wherein means are mounted on the dogging elementfor actuating the lock bolt.
 7. A unit according to claim 1, wherein thelever tumblers have side surfaces, and wherein at least one recess isprovided in at least one of the side surfaces of the lever tumblers, forreceiving a projection on the blocking element.
 8. A unit according toclaim 1, wherein the lever tumblers have side surfaces, and wherein atleast two recesses maybe provided in one of the side surfaces of thelever tumblers, for receiving a code reading projection on the blockingelement, whereby the lever tumblers provided with at least two recesseshave a number of release positions corresponding to the number ofrecesses in one of the side surfaces of said lever tumblers.
 9. A unitaccording to claim 1, wherein at least one latch pin is mounted on thedogging element and movable in a plane perpendicular to the movementdirection of the lever tumblers and adapted to coact with a groove on aninserted key, and at least one notch is provided on the lever tumblers.10. A unit according to claim 9, wherein the latch pin has acircumferentially extending flange which coacts with the groove on theinserted key in a manner such that when the wrong key is inserted, oneend of the pin will engage said notch, thereby blocking movement of thelever tumbler in relation to the dogging element.
 11. A key and a lockunit according to claim 1, comprising a key bit, wherein non-penetratingcode surfaces are provided on one side surface of the key bit, forcoaction with a plurality of lever tumblers.
 12. A key and a lock unitaccording to claim 9 and including a key bit provided with codesurfaces, wherein the spine of the key carries a groove for coactionwith a flange on a latch pin in the lock unit.